For riders who find that the majority of their riding is city driving bikes should a a severe and normal schedule for oil changes but they don't. IMHO this is because the problem may not be the oil, it may be that you ned a clutch cable adjustment. I've found that during Oct-Mar I ride almost exclusively in the city (too friggen cold on the highway) and my shifting does get harder. Every year I start with trying to extend my arm up time and when that doesn't work I adjust the clutch cable. I use the "A" oil and do changes at 7500 but I start getting a little resistance around 5000 that so far has been corrected with the cable adjustment.
Retired USAF, IYAAYAS!
2008 V-Star 1100 Custom Bobber project
2011 Crimson XR with Forged Highway Bars / Hard Bags / Passenger Backrest, Ness parts including Smooth Layback Plate Frame/Mount / Rad 3 Mirror / deep cut grips / drivers floorboards /shifter peg / brake peg / passenger pegs. Witchdoctor black rack, Lloydz filter / timing wheel / VFC III, 7Jurock windshield, Drag Specialties seat.